Hello, at first sorry for my English

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I am going to swap d16y8(obd2a) to b18c4(obd2b) from UKDM Civic.
My car is HCC 6gen EJ8, car harnesses are obd2a, d16y8 ecu had immobilizer.
As I know, I have to convert ECU plugs to fit obd2b ECU. I will do that using ECU pinouts form
http://www.turbod16.com/viewtopic.php?t=3572
But how about engine harness? My car's engine harnesses are 1-piece design, and b18c4 are 2-piece design. If I disconnect all plugs from d16y8(obd2a) engine , and connect directly to b18c4(obd2b) engine, will they fit?
Thank You.